[Conrad Slater]"If I could separate out the colour information from the colour image into a colour layer I could then use that to colour my other images (with a little bit of editing)."

It sounds like all you need to do is place the color layer above the monochrome layer and set it to the 'color' transfer mode. If you're looking for a more involved effect then you'll have to clarify what it is you're trying to do.

"all you need to do is place the color layer above the monochrome layer"

absolutely so. but how do I create a colour layer. The only way I've seen is to create a blank layer and colour it in BY HAND - which is nonsense because I have the colour information in another image.

I just want to use the colour information from one image and apply it to another.

I've explained the circumstances of the job - I am really putting across my situation badly; no one seems to understand me.

[Conrad Slater]"absolutely so. but how do I create a colour layer. The only way I've seen is to create a blank layer and colour it in BY HAND - which is nonsense because I have the colour information in another image."

That's what the 'color' transfer mode is. If you consider your two layers in terms of consisting of Hue, Saturation and Lightness (HSL) components then the color blend mode replaces the Hue and Saturation components of your lower layers with those of the blend layer. The resulting blend uses lightness from the lower layers and hue and saturation (the 'color') from the upper layer.

This is exactly what you'd asked for, but I imagine your situation is in fact more complex. The colors in the top layer will not match the colors that are suppose to be in the bottom layer unless they are exactly the same shot. This means that you will need to manually paint in your color layer, or smudge or otherwise push the colors around to match the lower shot. Unless you're trying to do something else entirely, which is why I asked what you're trying to accomplish.

[Conrad Slater]"I just want to use the colour information from one image and apply it to another."

If this is in fact what you want to do, then all you need to do is what I suggested in my previous post.